Porsche Enthusiasts Club Forum

It is currently Thu Mar 28, 2024 1:58 pm
Classic Line Insurance


All times are UTC [ DST ]




Post new topic Reply to topic  [ 10 posts ] 
Author Message
 Post subject: Hot start problems
PostPosted: Tue Mar 07, 2017 8:05 pm 
Offline

Joined: Tue Dec 13, 2016 4:58 pm
Posts: 4
TIPEC membership: 7792
Hi, I have a 1988 911 3.2 with a hot start problem. It starts first time when cold but when hot if it is turned off for about 15 mins it has problems starting.

I have changed the Temp Sensor, DME relay, fuel return valve and sent the DME control unit to Bosch and it was returned back with no faults.

Any ideas would be welcome. Thanks Tony


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Tue Mar 07, 2017 9:35 pm 
Offline
Site Admin
Site Admin

Joined: Thu Jan 01, 1970 1:00 am
Posts: 5523
Location: Rochester, Kent
TIPEC membership: 911
Try disconnecting the immobiliser.

_________________
Kent & South East London R.O

Join the Club

Silver 1989 911 Speedster
Midnight Blue 2004 996 C4S Cab
Tahoe Blue 1990 964 C2
Zenith Blue 1998 BoxsterSold
Guards Red 1992 944 S2 Cab gone but not forgotten
Mediterranean Blue BMW 530e


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Wed Mar 08, 2017 12:00 am 
Offline

Joined: Mon Nov 12, 2007 1:16 am
Posts: 4903
Location: Emsworth Hants
TIPEC membership: 993
Sounds like you may have a fuel vaporising issue? if you run the car until the engine is hot, switch off, how long after it is switched off before you begin to get the problem?


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Wed Mar 08, 2017 9:48 am 
Offline

Joined: Tue Dec 13, 2016 4:58 pm
Posts: 4
TIPEC membership: 7792
Hi about 15mins


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Wed Mar 08, 2017 12:10 pm 
Offline

Joined: Mon Nov 12, 2007 1:16 am
Posts: 4903
Location: Emsworth Hants
TIPEC membership: 993
So you have enough time for the fuel to vaporise and cause the issue, if you leave the motor to cool the engine starts ok? maybe worth checking out your high pressure fuel system.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Wed Mar 08, 2017 3:09 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sun Nov 04, 2007 8:43 pm
Posts: 12645
Location: Chatham, Kent
TIPEC membership: 4190
You need to be methodical. When it fails to start you need to pull a plug lead off, pop a spare plug in and see if you have ignition. Otherwise and quite likely you have a fuel problem. Crack a high pressure union and see if you have fuel in the HP circuit. Whilst it isn't starting and you pull a plug is it wet with fuel or bone dry.
Do this and come back to us with more info.

_________________
Jim

http://tipec.net/region_southeastlondon.php

2018 Mitsubishi Outlander PHEV
2005 Porsche Cayenne S Now sold!
2000 Jeep Grand Cherokee Now sold!
2010 Mazda MX5 Mk3.5 2.0 Sport Tech
2000 Porsche Boxster S SOLD!
1987 Porsche 944 2.5


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Wed Mar 08, 2017 4:36 pm 
Offline

Joined: Tue Dec 13, 2016 4:58 pm
Posts: 4
TIPEC membership: 7792
Thank you all. I will try that this weekend


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Fri Mar 10, 2017 12:22 pm 
Offline

Joined: Tue Dec 13, 2016 4:58 pm
Posts: 4
TIPEC membership: 7792
Hi Jim,

I ran the engine till it got to running temp and then turned it off and waited 15 mins and connected a spark plug and got someone to turn it over and there was no spark.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Mon Mar 12, 2018 11:11 pm 
Offline
User avatar

Joined: Sun Mar 11, 2012 11:03 am
Posts: 620
Location: Bolton U.K.
TIPEC membership: 6602
On my 944 S2 and 993 it was the crank sensor, both within 6 months of each other.

_________________
Porsche 944 S2 Coupe Guards Red
Porsche 993 Coupe Guards Red
Ducati 998 FE Red oc


Top
 Profile  
Reply with quote  
 Post subject: Re: Hot start problems
PostPosted: Tue Mar 13, 2018 1:37 pm 
Offline

Joined: Tue Dec 22, 2009 1:57 pm
Posts: 208
TIPEC membership: 0
Change the crank sensors, they will be at the end of their life by now even if it doesn't cure it. They are a wire coil so sensitive to heat, which is why they work when cold but not when hot


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group